Discussion on Dredging Construction under the Concept of Environmental Protection

The application of environmental protection concept in port and waterway dredging project can effectively reduce the impact and damage of port and waterway dredging construction on natural ecological environment, so as to realize the harmonious and sustainable development of ecological environment and social economy. In the actual dredging process of the waterway, construction management personnel should combine with the planning situation of waterway water and carry out the reasonable application of various construction technologies, so as to guarantee the construction quality in an all-round way. Based on this, this paper analyzes the dredging construction under the concept of environmental protection.

1. The role of environmental dredging construction

 1.1 Develop effective and suitable dredging schemes for ports and waterways

In the project, the possible pollution situation of a river channel can be investigated carefully, and the construction organization and design scheme can be arranged more reasonably according to the analysis and investigation results. Based on the analysis and investigation results, the pollutant is calculated. The dredging project construction plan is reasonably planned. The construction area of dredging work is scientifically and reasonably divided. The appropriate dredging technique is selected. The corresponding working system is formulated according to the plan, and the appropriate professional mechanical facilities are selected to ensure the normal dredging project of port and channel.

 1.2 Choose the right dredging time

In order to avoid the impact on the living environment of benthic organisms in the harbor, the construction should be carried out in a reasonable season and time. Another factor to consider is that the speed of seawater in coastal areas varies between high and low tides, making it difficult for suspended solids to sink.

 1.3 Choose the scientific method to treat sludge

The residual water and accumulated sludge must be filled with a scientific method. In the process of dredging and blowing-filling, the area of the mud discharge field should be increased to extend the natural precipitation time, and the vertical and horizontal ridges should be added in the mud discharge field to effectively control the construction surplus water. Sludge treatment methods mainly include biological dressing, centralized treatment, recycling, and closed stacking.

2. Environmental dredging construction

 2.1 Design scientific and reasonable dredging scheme of the harbor channel

First, the environment around the port-channel should be carefully investigated, and the factors and characteristics of the polluted sediment should be analyzed, and the preliminary paragraphs should be implemented according to the corresponding data. After that, a comprehensive evaluation is carried out according to the final result, and the corresponding construction scheme of port and channel dredging project is optimized according to the final result. The design work of each link should be carried out strictly in accordance with the corresponding order, scientific planning of the construction scope of the dredging project of port-channel, optimal selection of the most suitable construction method, and operation of dredging vessels and dredging equipment.

 2.2 Preparation for dredging construction

2.2.1 Setting-out survey

In the course of the lofting survey, the channel depth is evaluated in detail by using relevant measuring equipment, such as SDH-13d sounder, global positioning system, etc. Before the lofting and measuring work is carried out, the hydrological weather should be chosen as smooth as possible to ensure that the accuracy of relevant measuring instruments is not affected. In the actual measurement process, the precast slab or concrete can be used to make buoys, which can not only ensure the measurement accuracy but also reduce the cost of the channel dredging project.

2.2.2 Site layout

The site layout shall be conducted according to the relevant specifications of the bidding materials for the waterway dredging project. Considering regional water conservancy culture, urban overall planning, lake protection planning, and other factors comprehensively, the construction site layout is carried out on the premise of maintaining the previous water system ecosystem. Channel dredging project has a strong professional and layout process that needs to choose reasonable dredging equipment in the actual construction. According to the blowing distance and the requirements of the contract, select the appropriate wringing suction boat. At the same time, reasonable configuration of grab boat, mud pump, blowing mud boat, etc. are to ensure the smooth implementation of the overall construction.

 2.3 Choose dredging time and season scientifically

Choose the appropriate dredging period and season without affecting the survival of the habitat. Therefore, all kinds of work should take into full consideration the living creatures, and give priority to the winter with low-risk coefficient and less impact on the benthos. Choose a dry season to implement necessary dredging to avoid benthic growth time and reduce adverse factors to benthic. It is worth noting that it is also necessary to avoid as far as possible in the flow of relatively large spring tide or ebb time to be implemented. The dredging time of the port channel is determined mainly on the basis of the corresponding area, but it is generally chosen to be implemented in winter. The main reason is that winter is the lower stage of biological activities in the benthic habitat in port and waterway waters. In this period, the ecological and environmental protection of the whole water area was analyzed, and it was also the safest and most reliable construction stage. According to the requirements of environmental protection, dredging in winter should try to land the bottom mud, so that the diffusion degree of particles in the water area is relatively small.

 2.4 Strengthen water quality monitoring in dredging projects

During the dredging process, it is strictly forbidden for non-staff to carry out the construction area to minimize the impact of the outside on the surrounding water quality. At the same time, we should increase the detection of water quality in the construction area to master the water quality. The monitoring scope includes the concentration of water and mud, effective measures must be taken to strengthen the treatment of contaminated sediment, comprehensively improve the purification efficiency of water quality, and avoid secondary impact on the water quality around the dredging construction site of port and waterway.

 2.5 Strictly control the precision of dredging construction

In the dredging process of the harbor channel, dredging should be carried out reasonably according to the distribution of sediment. To avoid over-excavation, polluted sediment can be filled at the bottom of the filling area, followed by uncontaminated dredged soil covering the contaminated soil layer. The protection of the surrounding ecological environment can be strengthened from the source by reducing the quantity of sludge treatment. Therefore, we must strictly control the precision of construction, so as to ensure the scientific dredging technology of the port channel. For example, in the dredging process of the harbor channel, effective measures should be taken to avoid the spread of polluted sediment. In view of the leakage of polluted bottom sediment, the times of stirring polluted bottom sediment at the bottom of ports and rivers can be reduced to strengthen control and minimize the pollution caused by the leakage of bottom sediment. At the same time, the construction quality control should be strengthened in strict accordance with relevant laws and regulations to comprehensively improve the precision of the dredging technique of port and waterway. Due to the sediment thickness of polluted sediment in port and river waters ranging from 10cm to 15cm, the sediment thickness in some areas may exceed 1m. Therefore, the construction schedule is highly required.

conclusion

In short, with the rapid development of China’s economy, the importance of ports and waterways is increasing day by day, and many economic activities are highly dependent on ports. To improve the construction technology of port and waterway, the most direct effect is to improve the construction quality of port and waterway engineering, so as to provide the safest guarantee for the port’s shipping capacity. To a large extent, the port’s shipping capacity is directly reflected in the channel’s shipping capacity. The stronger the channel’s shipping capacity is, the stronger the port’s shipping capacity will be. Especially in the ecological environment, it is necessary to focus on strengthening control, so as to better meet the development requirements.